Gun perforator



ug W l41- J. o. Tow 2,252,996

GUN PERFORATOR AFiled Nov. 14, 1939 Patented Aug. 19., 1941 UNITEDl STATES 'PATENT OFFICE GUN PERFORATOR James 0. Tow, South Pasadena, Calif., assigner,

to Ira J. McCullough, Los Angeles, Calif.

Application November 14, 1939, Serial No. 304.332

17 Claims.

My invention relates in general to perforating guns oi the type employed to. perforate Well casings by ring projectiles therethrough, and relates in particular to a perforating gun having simplied construction and wherein reduced cost of operation and upkeep is accomplished without decrease in the effectiveness of the gun.

It is an object of the present invention to provide a novel and simple means whereby the bullets of a perforating gun of this character are held from outward movement in the gun bores until the explosive pressure resulting from the firing of a charge of explosive has built up to a high value, the result being that the projectiles are discharged from the gun at high velocity and readily penetrate several layers of well casing. In the prior art use of projectiles to perforate well casing, a number of methods of restraining the projectiles against outward move- -ment until a desired high explosive pressure has' been built up include shoulders, rings, flanges, and discs associated with the projectile. In my present invention such means are replaced by a relatively simple and economical means for accomplishing the desired result.

It is an object of the present invention to provide a multiple projectile comprising a number of projectile bodies connected at their inner ends by disjoinable means which holds the projectile bodies fromoutward movement in their respective gun bores until the explosive pressureapplied to the rear ends of the projectile becomes great enough to cause disjoinder of the disjoinable means, at which time the projectiles are simultaneously released so that the pressure of the products of explosion will propel them at high velocity through the gun bores.

It is an object of the invention to provide in 'a casing perforating gun. of the general character described, a body having a plurality of out- Wardly extending gun bores arranged so that the inner ends thereof lie in adjacent relation, and a projectile in each of the bores connected by a disjoinable holding or restraining means which prevents premature discharge of the projectiles from their respective gun bores.

It is an object of the invention to provide a perforating gun having a gun body with a pair of axially aligned gun bores extending out in opposite directions, means for applying a propelling gas pressure at the inner end of these gun bores, a projectile in each of the gun bores and disjoinable means connecting the inner ends of the projectile whereby the projectiles Will be held from outward movement in the gun bores until a prescribed gas pressure has been built up against the inner ends of the projectiles whereupon they will be simultaneously released and discharged.

A further object of the invention is to provide a projectile of simple form for use in a perforating gun of the character hereinabove described comprising a pair of projectile bodies substantially axially aligned with a recess between the inner ends thereof which is traversed in axial direction by a disjoinable connecting means.

A further object of the invention is to provide a multiple projectile comprising a bar having a recess intermediate the ends thereof, such recess forming a space which lies adjacent to or surrounds a disjoinable connecting means for the projectile bodies which are formed by the end portions of the bar. Y

Itis a further object of the invention to provide a perforator gun having a body built up of a number of short sections connected in end to end relation, each of these bodies having axially aligned bores extending outward therein in opposite directions and being adapted to receive connected projectile bodies, a firing charge chamber in each-body section and means whereby the firing of a charge in one firing charge chamber causes or produces the firing of a charge in an adjacent or succeeding firing charge chamber. A further object of the invention is to provide a perforating gun having a body with a plurality of gun bores arranged lengthwise thereof, a plurality of firing charge chambers connected with the gun bores and means which operate automatically upon the rlng of a charge in one of the ring charge chambers to re a charge in an adjacent or succeeding ring charge chamber, the firing means being arranged serially between the ring charge chambers.

It is a further object of the invention to provide a perforating gun of sectional form wherein the longitudinal spacing of the gun bores is maintained at small dimension by provision of firing charge chambers in the ends of threaded pins which are formed on the gun body sections and cooperate with threaded boxes to secure the sections operatively in end to end relation.

Further objects and advantages of the invention will be brought out in the following part of the specification.

Referring to the drawing which is for illustrative purposes only:

.Fig. 1 is a sectional view of a preferred embodiment of my invention.

Fig. 2 is a cross-section taken as indicated by the line 2--2 of Fig. 1.

Fig. 3 is a partly sectioned view of an alternative form of multiple projectile.

Fig. 4 is a view of another multiple projectile.

Fig. 5 is a fragmentary cross-sectional view to indicate the manner in which groups of projectiles may be propelled by a single body of explosive.

Fig. 6 is a partly sectioned elevational view showing projectiles secured by another type of connecting means.

In Fig. 1 I show a perforator gun having a body II comprised of an upper section I2, intermediate sections I3, and a bottom section I4. The upper section I2 is provided with a threaded counter bore I5 which receives an externally threaded body I6 forming the lower part of a suspension means I1 of the type disclosed in the copending application of Ira J. McCullough Serial No. 258,606, led February 2'1, 1939, for Gun perforator. A chamber I8 lies below and in communication with the threaded counterbore I5, and a removable cylindrical block I9 is receivable in this chamber, such block I9 having a bore 20. the upper end of which receives a cartridge 2| which serves as an igniting or firing means for a charge of explosive 22 contained in a firing charge chamber 23 which lies below the chamber I8. The cartridge 2I may be iired by means of a ring pin 24 which extends through an opening 25 in the threaded member I6 and through packing means 26 and a replaceable gland 21 carried by the member I6. When it is desired to fire the cartridge 2I, the firing pin 24 is driven downward by suitable means, which may include a hammer or weight which is passed downward around a cable which is connected to the suspension means I1, all as explained in the copending McCullough application referred to in the foregoing. The ring charge chamber 23 is preferably located on the vertical axis of the section I2, and a passage 28 extends downward therefrom to communicate with the inner ends of gun bores 29 which extend diametrically outward through opposite faces .of the section I2. These gun bores 29 are preferably axially aligned and may be formed by a single diametral opening 29' which is drilled through the section I2 from one side to the other thereof.

The upper section I2 and the intermediate sections I3 each have a downwardly projecting externally threaded pin 30, and the intermediate sections I3 and the bottom sections I4 each have at the upper end thereof a threaded box 3I to make threaded engagement with a pin 30, so that the sections I2, I3, and I4 may be connected in end to end relation to form the gun body II, as shown in Fig. 1. In the lower end of each pin 3U there is a recess or counter-bore to form a firing charge chamber 32, and extending upward from each chamber 32 there is a passage 33 to connect it with the next preceding firing charnber. Each passage 33 has a threaded portion 34 and a counterbore 35 to receive the threaded shank 36 and the head 31 of a restraining means having form of a plug or screw 38 having a longitudinal opening 39. Each section I3 and I4 has a passage 40 extending downward from the bottom of the box 3l thereof to provide for communication of each ring charge chamber 32 with gun bores formed in each section next following the pins 3D in which the firing charge chambers 32 are located. For example, in the intermediate section I3 I have shown the passages 40 connected to the inner ends of laterallyand outwardly extended gun bores 29, and in the bottom section I4, I have shown the passage 40 connected to a space 4I lying between the inner ends of gun bores 42 formed in diametrally aligned replaceable barrels 43 which are externally threaded as indicated at 44 and screw into threaded openings 45 in the bottom section The gun bores of the device, comprising the bores 29 and 42, receive projectile bodies 46 as shown in the upper section I2 of Fig. 1. 'Each group of gun bores, for example, the two gun bores 29 of upper section I2 receives interconnected projectile means consisting of projectile bodies 46 disposed in the gun bores 29 with their inner ends in adjacent relation and being connected by disjoinable means 41, which, as shown in section I2 of Fig. 1, may comprise an axially extending neck formed between the projectile bodies 46 as the result of cutting an annular groove or recess 48 around the continuous bar of metal from which the connected projectile bodies 46 are formed. It will be noted that the annular channel 48 provides between the inner ends of the projectile bodies 46 a recess which communicates through the passage 28 with the firing charge chamber 23.

The multiple projectile 49 may be quickly and simply machined from bar stock of desired diameter. The section of stock in the making of the composite bullet has the ends thereof sharpened to provide points 5I) for the projectile bodies, and the cutting of the annular channel 48 intermediate the ends of the piece of stock divides the same into two cooperating bodies 46 which are connected by the neck 41. Means are provided for holding the multiple bullet structure 49 in the bores 29. This multiple projectile 49 may be tinned and then forced into the bores 29 to the centralized position shown and means may be applied to hold the multiple projectile 49 in place, such means may consist of a small amount of quickly solidiable liquid material 52 which is poured into the ends ofthe bores 29, and the holding means may comprise rubber plugs 53 which are pressed into the ends of the bores 29 so as to be lodged against the points 56 of the projectile bodies 46, the bores 29 being thereby eiectively sealed so as to assure against entry of water or other liquid therethrough into the ring charge chamber 23.

In the iiring of the gun, the following effects are attained. When the firing pin 24 is driven down so as to discharge the cartridge 2I and ignite the firing charge 22 in the chamber 23, the burning of the firing charge 22 rapidly and substantially instantaneously builds up a. high pressure of propelling gaseous products in the recess 48 and accordingly against the inner ends of the projectile bodies 46. When the outward force exerted against the exposed inner end faces of the projectile bodies 46 exceeds the tensile or rupturing strength of the neck 41 and the other forces tending to hold the projectile bodies 46 from movement, such neck will part and the pressure of the propelling gas against the inner ends of the projectile bodies 46 will drive the same at high velocity out through the gun bores 29. A portion of the products from the explosion of the firing charge 22 in the chamber 23 will pass down through the passage 39 of the restraining means 36 to the iiring charge chamber 32 next in downwardly succeeding order from the chamber 23. The heat and/or pressure of the explosion products which enter the chamber 32 through the restricted passage 39 will fire the charge therein and the explosive pressure resulting therefrom will discharge from their respective bores 29 the projectile bodies which lie immediately below the firing charge chamber 32. It will be seen from the foregoing that I have provided a gun body consisting of detachable sections, with firing charge chambers so placed `therein that they will be open for recharging when the sections are disconnected and will be closed and sealed when the sections are connected in end to end relation, and that I have also provided in each of the gun body sections means for effecting the serial or progressive firing of the firing charges when the sections are connected in end to end relation.

With relation to the neck 41 lwhich connects the inner ends of two projectile bodies d6 I employ the term disjoinable means to embrace the different arrangements and constructions whereby joinder and disjoinder oi associated projectile bodies may be accomplished, and whereby such projectile bodies are joined and held against outward movement until a high propelling gas pressure has been built up against the inner ends thereof whereupon disjoinder of these projectile bodies releases the same and permits them to be propelled at high velocity out through the gun bores.

To illustrate the manner in which this joinder and disjoinder of projectile bodies may be otherwise attained, I have in Figs. 3 and 4 shown multiple projectiles 60 and 6I. The multiple projectile 60 comprises a .projectile body 62 having a stem 63 projecting from the inner end thereof into an opening 64 in the inner end of an adjacent projectile body 65. Inter-engagement between the stem 63 and the projectile body 66 may'be accomplished by use of threads 66 which will strip when a separating force of suilicient intensity is applied to the inner ends of the projectile bodies 62 and 65, thereby accomplishing a disjoinder of these projectile bodies 62 and 65. In Fig. 4, the multiple projectile 6| comprises a bar 61 having sharpened ends 68 and having a. transverse opening 69 drilled between the ends thereof so as to form projectile bodies 10 connected by Wall portions 1| which lie on diametrally opposite sides of the opening 69. In the use of the term axially extending as applied to the disjoinable means connecting associated projectile bodies, I include not only a metal connecting element lying in coaxial relation to the projectile bodies, for example, the neck 41 and the stem 63, but also connecting metal elements which extend in the general direction of the axis of a multiple projectile, for example, the Wall portions 'Il of Fig. 4 which are left on opposite sides of the opening 69 when such an opening is drilled through the center of a bar from which a multiple projectile is formed. The opening 69 pro vides a recess having the same function as the annular recess 48 of the multiple projectile 49 disclosed in the upper section i2 of Fig. 1. The explosive pressure of a. firing charge is applied within the opening 69 to urge the projectile bodies 10 outward, and when this pressure reaches a sumciently high value the connecting metal portions 1i will fail in tension and disjoinder of the projectile bodies 10 will result.

In Fig. 5 I show an alternative form of my invention comprising a gun body section having a threaded box 16 at one end thereof and a threaded pin 11 at the other end thereof. A liring charge chamber 18 extends downward from the bottom of the threaded box 18 and a passage '56 leads downward from this firing charge chamber 16 to the end of the pin 11, such passage 19 having a threaded portion 86 into which a restraining plug Il is screwed, this restraining plug 3l being a replaceable element and having an opening 82 -of small diameter therethrough.

through which igniting llame and/or pressure is transmitted from the ignition oi' a charge of powder in the chamber 16 to the next succeeding firing charge chamber. The section 15 has diametral openings 82 and 83 extending through from side to side thereof in planes which cross at substantially right angles. In each of the bores d2 and S8 a double projectile 49 is placed in centralized position. 'I'he ring charge chamber il@ is of such large size that a heavy charge of explosive may be placed therein.. When this charge of explosive is fired in the manner hereinabove described relative to Fig. 1, or in any other manner, the enormous pressure built up in the passage it will discharge the projectile body sections 65 outward in. the respective portions of the bores i2 and 83 which they occupy.

In the forms of multiple projectile described in detail to the foregoing, the projectile bodies are connected by metal parts adapted to rupture and thereby release the projectile bodies. In'Fig. 6 I show a dual projectile having projectile bodies 9G and Si with their rear ends connected by cementitious means 92 or means adapted to be broken down by heat from the burning of the associated explosive charge. The connecting means 92 is in the present instance a layer of solder or metal adapted to melt or disintegrate under the application of heat at the temperature produced by the burning -of a powder charge in the perforating gun.

I claim as my invention:

1. In a perforating gun of the character described, the combination of: a gun body having a plurality of gun bores to receive projectiles therein, and means for applying a gas pressure against the inner ends of said projectiles; projectiles in said gun bores; and restraining means at the inner ends of said projectiles operative when the gas pressure against the inner ends of said projectiles has built up to simultaneously release said projectiles so that said gas pressure may then discharge the same at high'velocity from said gun bores.

2. In a perforating gunof the character described, the combination of: a gun body having a plurality of gun bores to receive projectiles therein, and means for applying a gas pressure against the, inner ends of said projectiles; projectiles in said gun bores; and disjoinable means connecting the inner ends of said projectiles so as to hold said projectiles from outward movement in said bores until a gas pressure is built up against the inner ends of said projectiles suiiicient to cause disjoinder of said disjoinable means.

3. In a perforating gun of the character described, the combination of: 'a gun body having a pair of gun bores to receive projectiles and extending outwardly in substantially opposite directions, and means for applying gas pressure against the inner ends of said projectiles; a projectile in each of said bores; and disjoinable means connecting the inner ends of said projectiles to restrain movement of said projectiles outwardly in said bores until a gas pressure is built up against the inner ends of said projectiles suiiicient to cause disjoinder of said disjoinable means.

4. In a perforating gun of the character described, the combination of: a gun body having a pair of axially aligned gun bores to receive projectiles and extending outwardly in substantially opposite directions, and means for applying gas pressure against the inner ends of said projectiles; a projectile in each of said bores;

disjoinable means connecting the inner ends of said projectiles to restrain movement of said projectiles outwardly in said bores until a gas pressure is built up against the .inner ends of said projectiles suillcient to cause disjoinder of said disjoinable means; and means for holding said projectiles in said gun bores.

5. In a perforating gun of the character described, the combination of: a gun body having a pair of axially aligned bores extending outwardly in opposite directions, there being means operative to apply a propelling gas pressure to the inner ends of said bores; and a double projectile comprising a pair of axially aligned projectile bodies connected together by disjoinable means which extends from one projectile body to the other projectile body and is so formed that there is a space between the inner ends of said projectile bodies.

6. In a perforating gun of the character described, the combination of: a gun body having a pair of axially aligned bores extending outwardly in opposite directions, there being means operative to apply a propelling gas pressure to the inner ends of said bores; and a double projectile comprising a pair of axially aligned projectile bodies connected together by disjoinable means comprising a neck of less diameter than said projectile bodies and which parts and disconnects said projectile bodies when the force applied to the inner ends of said projectile bodies exceeds the tensile strength of said neck.

'7. In a perforating gun of the character described, the combination of: a gun body having a bore extending through from side to side thereof and a ring charge chamber communicating with said'bore between the ends thereof; means for igniting a charge in said firing charge chamber; and a double projectile in said bore comprising a member having a recess intermediate the ends thereof communicating with said firing charge chamber.

8. In a perforating gun of the character described, the combination of: a gun body having a bore extending through from side to side thereof, a ring charge chamber axially offset from said bore and a passage connecting said firing charge chamber to an intermediate portion of said bore; means for igniting a charge in said ring charge chamber; and a double projectile in said bore having a recess intermediate the ends thereof communicating with said firing charge chamber.

9. In a perforating gun of the character described, the combination of: a gun body having a bore extending through from side to side thereof and a firing charge chamber communicating with said bore between the ends thereof; means for igniting a charge in said ring charge chamber; a double projectile in said bore having a recess therein intermediate the ends thereof communicating with said iiring charge chamber; and means engaging said recess to position said projectile in said bore.

10. In a perforating gun of the character described, the combinationof: a body section having means at the ends thereof whereby it may be connected to adjacent body sections, a transverse bore extending through from side to side thereof and passage means extending from end to end thereof, there being a ring charge chamber having communication with an intermediate portion of said bore and also having communication with said passage means; a double projectile having a recess intermediate its ends, placed in said bore in such position that suc-h recess will lie in said intermediate portion of said bore; and restraining means in said passage means.

11. In a perforating gun of the character described, the combination of: a body section having a pin at one end thereof and a box at the V other end thereof, a transverse bore extending through from side to side thereof, a firing charge chamber in the end of said pin, and passage means connecting said firing charge chamber with an intermediate portion of said bore and with the bottom of said box, said passage means also comprising a restraining means; a double projectile having a recess intermediate its ends, placed in said bore in such position that said recess will lie in said intermediate portion of said bore; and restraining means in said passage means.

12. A gun section of the character described, comprising: a metal body having connecting means at opposite ends thereof whereby a series of such bodies may be connected in end to end relation; a gun bore extending out through a side of said body, the inner end of said gun bore having communication with one end of said body; a passage leading from the inner end of said gun bore to the other end of said gun body and being enlarged at the extremity thereof to provide a firing charge chamber; and restraining means in said passage between said firing charge chamber and said gun bore.

13. In a gun section of the character described, the combination of: a body having an internally threaded box at one end and an externally threaded pin at the other end, a recess in said pin end of said body to form a firing charge chamber, a passage extending from said recess to the box end of said body, and a gun bore extending in from a side of said body, the inner end of said body communicating with said passage; and la projectile in said gun bore.

14. In a perforating gun of the character described, the combination of: a gun body having a plurality of gun bores to receive projectiles therein, and means for applying a gas pressure against the inner ends of said projectiles; projectiles in said gun bores; and disjoinable means connecting the inner ends of said projectiles so as to hold said projectiles from outward movement in said bores while a gas pressure is being built up against the inner ends of said projectiles, the disjoinder of said disjoinable means releasing said projectiles so that they may be then propelled out through said bores by said gas pressure.

15. In a perforating gun of the character described, the combination of: a gun body having a plurality of gun bores to receive projectiles therein, and means for applying a gas pressure against the inner ends of said projectiles; projectiles in said gun bores; and disjoinable means connecting the inner ends of said projectiles so.

as to hold said projectiles from outward movement in said bores while a gas pressure is being built up against the inner ends of said projectiles, said means being disjoinable by heat to release said projectiles so that they may be then propelled out throughV said bores by said gas pressure.

16. In a perforating gun of the character described, the combination of: a gun body having a bore extending in from a face thereof; a firing charge chamber communicating with the inner portion of said bore; means to explode a charge in said chamber; a projectile in said bore; and means to delay the movement of said projectile when said charge is exploded, comprising a body o1' metal connected to the inner portion of said projectile and being disjoinable by heat from ithe burning of said charge so as to release said projectile for movement.

17. In a perforating gun of the character described, the combination of: a gun body having a bore extending in from a face thereof; a firing charge chamber; means to explode a charge in said chamber; a projectile in said bore having a restraining means comprising a body in spaced relation to the rear end thereof and being connected .to the rear end of the projectile by disjoinable means; and walls forming a passage disposed so as to direct the products of explosion from the firing charge chamber to the zone of said bore between said projectile and said body.

JAMES O. TOW. 

